A digital image processing apparatus is disclosed. The apparatus increases input pixel intensity values in an edge region of input image data to form output pixel intensity values. The input pixel intensity values are varyingly increased depending on a location of the input pixel values within the edge region. The output values are printed on an edge region of a print sheet. A printer prints the output intensity pixel values on a print sheet. The invention allows printing of digital images to the edge of a print sheet without accumulating a great deal of toner at the edge of the sheet or overburdening a toner cleaning device.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A digital image processing apparatus for adjusting input pixel intensity values in an edge region of input image data to form corresponding output pixel intensity values that are printed on an edge region of a print sheet, the apparatus comprising: an edge processor for adjusting the input pixel intensity values of the edge region of the input image based at least partially upon a location of the corresponding output pixel intensity values in the edge region of the print sheet to form output intensity pixel values in said edge region of said print sheet that fade toward a background intensity value moving from an inner portion to an outer portion of said print sheet edge region, wherein the edge processor adjusts only input intensity pixel values in the edge region that do not already meet a predetermined intensity level pixel value; and, a printer for printing the output intensity pixel values on an edge region of a print sheet, said edge region of said print sheet located at a periphery of said print sheet.
2. The apparatus as set forth in claim 1 further including: a look-up table memory including look-up tables for mapping the input intensity pixel values at the edge region of the input image to the output intensity pixel values, wherein the edge processor accesses the look-up table memory.
3. The apparatus as set forth in claim 1 wherein the edge processor includes a scaling processor for adjusting the input intensity pixel values at the edge region of the input image to form the output intensity pixel values.
4. The apparatus as set forth in claim 1 wherein the edge processor adjusts an input intensity pixel value by factor that is dependent on the location of the pixel value between the inner portion and outer portion of the edge region of the printed sheet.
5. The apparatus as set forth in claim 4 wherein the factor increases from the inner portion to the outer portion of the edge region of the printed sheet.
6. The apparatus as set forth in claim 1 wherein the predetermined intensity pixel value changes depending upon the location of the input intensity pixel value in the edge region between an inner edge region and an outer edge region.
7. The apparatus as set forth in claim 1 wherein the edge region of the print sheet corresponding to the edge region of the input image data is less than 15 mm in width.
8. The apparatus as set forth in claim 4 wherein the print sheet is generally of size A4 and the edge region of the print sheet is approximately 6 mm in width.
9. A method of digital image processing to adjust input pixel intensity values in an edge region of input image data to form output pixel intensity values that are printed on a peripheral edge region of a print sheet, the method comprising: adjusting the input pixel intensity values for the edge region of the input image depending at least partially upon a location of each of said input pixel intensity values in the edge region to form output intensity pixel values, said step of adjusting including adjusting input intensity pixel values in the edge region that satisfy a predetermined intensity level pixel value threshold; and, printing the output intensity pixel values on a peripheral edge region of a print sheet.
10. The method as set forth in claim 9 wherein the step of adjusting includes: accessing a look-up table; and mapping the input intensity pixel values to the output intensity pixel values according to the look-up table.
11. The method as set forth in claim 9 wherein the step of adjusting includes: applying a mathematical equation to the input intensity pixel values to form the output grey scale pixel values.
12. The method as set forth in claim 9 wherein the step of adjusting includes: adjusting an input intensity pixel value by a factor that is dependent on the location of the corresponding output intensity pixel value between an inner edge and an outer edge of the edge region of the printed sheet.
13. The method as set forth in claim 12 wherein the factor increases from the inner edge to outer edge of the edge region of the printed sheet.
14. The method as set forth in claim 9 wherein the predetermined intensity pixel value threshold changes moving from an inner edge to an outer edge of the edge region of the printed sheet.
15. The method as set forth in claim 9 wherein the step of printing includes: printing on a print sheet, wherein the edge region of the print sheet that corresponds to the edge region of the input image data is less than 15 mm in width.
16. The method as set forth in claim 15 wherein the print sheet is generally of size A4 and the edge region of the print sheet is approximately 6 mm in width.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
December 18, 1998
October 22, 2002
Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.